Rework live location shares stream by ganfra · Pull Request #6385 · matrix-org/matrix-rust-sdk

ganfra · 2026-03-31T15:08:55Z

Motivation

The previous observe_live_location_shares API was limited: it emitted individual beacon events one at a time, excluded the own user's shares, provided beacon_info only as an Option (requiring a state fetch per
event), and had no awareness of share start/stop lifecycle.

What changed

New stream semantics (matrix-sdk)

Room::observe_live_location_shares is replaced by Room::subscribe_to_live_location_shares. The new method returns a Stream<Item = Vec> that always emits the full snapshot of currently active
shares:

Seeded from the event cache: on subscription, the stream immediately emits the current active shares loaded from cached beacon events.
Includes own user: own shares are no longer filtered out.
Handles lifecycle: a beacon_info state event with live: false removes the user from the active list and triggers a stream update.
Fast path for tracked users: when a new beacon arrives for a user already in the map, their cached beacon_info is reused instead of re-fetching from the state store.
Bug fix: a beacon event for a user with a non-live beacon_info no longer incorrectly triggers a stream update.
beacon_info on LiveLocationShare is now BeaconInfoEventContent (non-optional).

FFI bindings (matrix-sdk-ffi)

Room::observe_live_location_shares is similarly replaced by Room::subscribe_to_live_location_shares, which takes a LiveLocationShareListener callback (new interface) called with the full updated
Vec on every change.

I've documented the public API Changes in the appropriate CHANGELOG.md files.
This PR was made with the help of AI.

Signed-off-by:

codspeed-hq · 2026-03-31T15:20:20Z

Merging this PR will not alter performance

✅ 50 untouched benchmarks

_{Comparing ganfra/live_location_shares_stream (074eec7) with main (a65fec3)}

codecov · 2026-03-31T19:25:13Z

Codecov Report

❌ Patch coverage is 79.36508% with 26 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.85%. Comparing base (a65fec3) to head (074eec7).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
crates/matrix-sdk/src/live_location_share.rs	80.53%	13 Missing and 9 partials ⚠️
crates/matrix-sdk/src/room/mod.rs	69.23%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6385      +/-   ##
==========================================
- Coverage   89.87%   89.85%   -0.03%     
==========================================
  Files         378      378              
  Lines      103445   103552     +107     
  Branches   103445   103552     +107     
==========================================
+ Hits        92973    93047      +74     
- Misses       6902     6922      +20     
- Partials     3570     3583      +13

☔ View full report in Codecov by Sentry.
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stefanceriu · 2026-04-01T11:48:45Z

crates/matrix-sdk-ui/src/room_list_service/mod.rs

-const DEFAULT_ROOM_SUBSCRIPTION_EXTRA_REQUIRED_STATE: &[(StateEventType, &str)] =
-    &[(StateEventType::RoomPinnedEvents, "")];
+const DEFAULT_ROOM_SUBSCRIPTION_EXTRA_REQUIRED_STATE: &[(StateEventType, &str)] = &[
+    (StateEventType::RoomPinnedEvents, ""),
+];


This feels unnecessary, ai? 🤔

Yeah I think I had first added the beacon_info to this list instead

stefanceriu · 2026-04-01T12:03:02Z

crates/matrix-sdk/src/live_location_share.rs

+pub struct LiveLocationShares;
+
+impl LiveLocationShares {


I think I would've preferred it if this service would work on top of the ObservableVector and setup its observers in the constructor, similar to all the other list based services we're building, for consistency.

A lot of these services live on the UI crate level but room_directory_search makes use of it on the sdk crate level.

I thought we said we didn't want ObservableVector for such api? But happy to change if you think it's better.

Ah, I see what caused the confusing: I though you were asking if we should bother tracking atomic updates and I thought it's fine, we can just reload the whole list every time. All while still using ObservableVector e.g. space filters

matrix-rust-sdk/crates/matrix-sdk-ui/src/spaces/mod.rs

Lines 488 to 489 in eb51c86

space_state.space_filters.clear();

space_state.space_filters.append(new_filters);

I think it would be great if you can change it so the handlers, the helpers and everything else is contained withing this LiveLocationShares service 🙏

Ok I see! I've been using Stream api as it's also used in other places in the sdk.

stefanceriu · 2026-04-01T12:05:11Z

crates/matrix-sdk/src/room/mod.rs

+    /// Get all currently active live location shares in the room.
+    ///
+    /// Returns a list of all users who are currently sharing their live
+    /// location (excluding the current user), along with their latest known
+    /// location if available in the event cache.
+    pub async fn get_active_live_location_shares(
+        &self,
+    ) -> Result<Vec<LiveLocationShare>> {
+        crate::live_location_share::get_active_live_location_shares(self).await
+    }
+


I would expected all usages to go through LiveLocationShares, not bypass that whole layer. (See my other comment about ObservableVector)

crates/matrix-sdk/src/live_location_share.rs

crates/matrix-sdk/tests/integration/room/beacon/mod.rs

…tate

…r CI

# Conflicts: # bindings/matrix-sdk-ffi/CHANGELOG.md

crates/matrix-sdk/src/live_location_share.rs

…t_cache

ganfra · 2026-04-03T16:01:53Z

Ok @stefanceriu the PR is ready to re-review I think :D

stefanceriu

This is looking great, just a couple of small comments!

I'll be out for a bit so I'm going to let the review gods choose somebody else to help you out with a merge (squash 🙏 ) next week 🚀.

stefanceriu · 2026-04-04T18:43:57Z

bindings/matrix-sdk-ffi/src/room/mod.rs

+    /// The listener is called immediately with the current list of shares as a
+    /// `Reset` update, then called again with incremental updates whenever the
+    /// list changes (location updates, shares starting/stopping).
+    pub async fn subscribe_to_live_location_shares(


Should this just return the LiveLocationShares "service" so the final user can do whatever they need with it? (similar to the ThreadListService, SpaceService etc.?

stefanceriu · 2026-04-04T18:45:14Z

bindings/matrix-sdk-ffi/src/room/mod.rs

-                    user_id: event.user_id.to_string(),
-                }])
+            // Keep live_location_shares alive to preserve event handlers.
+            let _live_location_shares = live_location_shares;


It's probably best we let the final user worry about lifetimes.

stefanceriu · 2026-04-04T18:47:05Z

bindings/matrix-sdk-ffi/src/live_location_share.rs

    pub location: LocationContent,
-    /// A timestamp in milliseconds since Unix Epoch on that day in local
-    /// time.
+    /// A timestamp in milliseconds since Unix Epoch on that day in local time.


This is actually origin_server_ts as far as I can tell so not sure what local times means.

stefanceriu · 2026-04-04T18:49:13Z

crates/matrix-sdk/src/room/mod.rs

    ///
    /// Returns an error if the event is redacted, stripped, not found or could
    /// not be deserialized.
    pub(crate) async fn get_user_beacon_info(


I wonder if we should just fold this into LiveLocationShares now 🤔

stefanceriu · 2026-04-04T18:49:54Z

crates/matrix-sdk/src/live_location_share.rs

-    pub beacon_info: Option<BeaconInfoEventContent>,
    /// The user ID of the person sharing their live location.
    pub user_id: OwnedUserId,
+    /// The user's last known location, if any beacon has been received.


Techincally the "asset"'s location

ganfra requested a review from a team as a code owner March 31, 2026 15:08

ganfra requested review from bnjbvr and stefanceriu and removed request for a team March 31, 2026 15:08

ganfra force-pushed the ganfra/live_location_shares_stream branch from fb8bd4d to 2cf6859 Compare April 1, 2026 06:48

bnjbvr removed their request for review April 1, 2026 08:50

stefanceriu reviewed Apr 1, 2026

View reviewed changes

ganfra added 8 commits April 2, 2026 17:32

Add StateEventType::BeaconInfo to the SS required states

4e2e919

Rework subscribe_to_live_location_shares methods

af2a178

refactor(live_location_share): include own user's shares in stream

7dac87b

refactor(live_location_share): improve tests and cover edge cases

bcf7a35

refactor(live_location_share): fix tests related to new SS required s…

70728dc

…tate

refactor(live_location_share): ensure beacon timeout is big enough fo…

91eaefc

…r CI

doc : update changelogs

930e3fd

# Conflicts: # bindings/matrix-sdk-ffi/CHANGELOG.md

refactor(live_location_share) : use ObservableVector to holds shares

1ab091a

ganfra force-pushed the ganfra/live_location_shares_stream branch from 7baa551 to 1ab091a Compare April 2, 2026 15:33

refactor(live_location_share) : continue to iterate

543555f

This was referenced Apr 2, 2026

Start, send and stop live location element-hq/element-x-ios#5333

Closed

Start send and stop functions of the LiveLocationManager element-hq/element-x-ios#5348

Merged

ganfra added 2 commits April 3, 2026 10:06

refactor(live_location_share) : remove the event_cache early return

5370b93

refactor(live_location_share) : iterate on integration tests

5859ac0

stefanceriu reviewed Apr 3, 2026

View reviewed changes

crates/matrix-sdk/src/live_location_share.rs Show resolved Hide resolved

ganfra added 3 commits April 3, 2026 17:33

refactor(live_location_share) : fix integration tests relying on even…

66a1244

…t_cache

doc : update changelogs

0e1aa9d

refactor(live_location_share) : make clippy happy

074eec7

ganfra requested a review from stefanceriu April 3, 2026 16:01

stefanceriu reviewed Apr 4, 2026

View reviewed changes

stefanceriu requested review from a team and bnjbvr and removed request for a team April 4, 2026 18:53

	space_state.space_filters.clear();
	space_state.space_filters.append(new_filters);

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ganfra commented Mar 31, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Motivation

What changed

New stream semantics (matrix-sdk)

FFI bindings (matrix-sdk-ffi)

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Merging this PR will not alter performance

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ganfra commented Apr 3, 2026

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